Isotopes of selenium
2527020
211975579
2008-05-12T22:29:53Z
JWB
273993
link Se-79
'''[[Selenium]]''' ('''Se''') has six naturally occurring [[isotope]]s, five of which are stable: <sup>74</sup>Se, <sup>76</sup>Se, <sup>77</sup>Se, <sup>78</sup>Se, and <sup>80</sup>Se. The last three also occur as [[fission products]], along with [[Se-79|<sup>79</sup>Se]] which has a [[halflife]] of 295,000 years, and <sup>82</sup>Se which has a very long half life (~10<sup>20</sup> yr, decaying via double beta decay to [[Krypton|<sup>82</sup>Kr]]) and for practical purposes can be considered to be stable. 23 other unstable isotopes have been characterized.
<br />Standard atomic mass: 78.96(3) [[unified atomic mass unit|u]]
== Table ==
{| class="wikitable" style="font-size:95%; white-space:nowrap"
! rowspan="2" | nuclide<br />symbol
! Z([[proton|p]])
! N([[neutron|n]])
! <br />isotopic mass (u)<br />
! rowspan="2" | half-life
! rowspan="2" | nuclear<br />spin
! rowspan="2" | representative<br />isotopic<br />composition<br />(mole fraction)
! rowspan="2" | range of natural<br />variation<br />(mole fraction)
|-
! colspan="3" | excitation energy
|-
| <sup>65</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 31
| 64.96466(64)#
| <50 ms
| 3/2-#
|
|
|-
| <sup>66</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 32
| 65.95521(32)#
| 33(12) ms
| 0+
|
|
|-
| <sup>67</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 33
| 66.95009(21)#
| 133(11) ms
| 5/2-#
|
|
|-
| <sup>68</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 34
| 67.94180(4)
| 35.5(7) s
| 0+
|
|
|-
| <sup>69</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 35
| 68.93956(4)
| 27.4(2) s
| (1/2-)
|
|
|-
| style="text-indent:1em" | <sup>69m1</sup>Se
| colspan="3" style="text-indent:2em" | 39.4(1) keV
| 2.0(2) µs
| 5/2-
|
|
|-
| style="text-indent:1em" | <sup>69m2</sup>Se
| colspan="3" style="text-indent:2em" | 573.9(10) keV
| 955(16) ns
| 9/2+
|
|
|-
| <sup>70</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 36
| 69.93339(7)
| 41.1(3) min
| 0+
|
|
|-
| <sup>71</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 37
| 70.93224(3)
| 4.74(5) min
| 5/2-
|
|
|-
| style="text-indent:1em" | <sup>71m1</sup>Se
| colspan="3" style="text-indent:2em" | 48.79(5) keV
| 5.6(7) µs
| 1/2- to 9/2-
|
|
|-
| style="text-indent:1em" | <sup>71m2</sup>Se
| colspan="3" style="text-indent:2em" | 260.48(10) keV
| 19.0(5) µs
| (9/2)+
|
|
|-
| <sup>72</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 38
| 71.927112(13)
| 8.40(8) d
| 0+
|
|
|-
| <sup>73</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 39
| 72.926765(11)
| 7.15(8) h
| 9/2+
|
|
|-
| style="text-indent:1em" | <sup>73m</sup>Se
| colspan="3" style="text-indent:2em" | 25.71(4) keV
| 39.8(13) min
| 3/2-
|
|
|-
| <sup>74</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 40
| 73.9224764(18)
| STABLE
| 0+
| 0.0089(4)
|
|-
| <sup>75</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 41
| 74.9225234(18)
| 119.779(4) d
| 5/2+
|
|
|-
| <sup>76</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 42
| 75.9192136(18)
| STABLE
| 0+
| 0.0937(29)
|
|-
| <sup>77</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 43
| 76.9199140(18)
| STABLE
| 1/2-
| 0.0763(16)
|
|-
| style="text-indent:1em" | <sup>77m</sup>Se
| colspan="3" style="text-indent:2em" | 161.9223(7) keV
| 17.36(5) s
| 7/2+
|
|
|-
| <sup>78</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 44
| 77.9173091(18)
| STABLE
| 0+
| 0.2377(28)
|
|-
| [[Selenium-79|<sup>79</sup>Se]]
| style="text-align:right" | 34
| style="text-align:right" | 45
| 78.9184991(18)
| 2.95(38)E+5 a
| 7/2+
|
|
|-
| style="text-indent:1em" | <sup>79m</sup>Se
| colspan="3" style="text-indent:2em" | 95.77(3) keV
| 3.92(1) min
| 1/2-
|
|
|-
| <sup>80</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 46
| 79.9165213(21)
| STABLE
| 0+
| 0.4961(41)
|
|-
| <sup>81</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 47
| 80.9179925(22)
| 18.45(12) min
| 1/2-
|
|
|-
| style="text-indent:1em" | <sup>81m</sup>Se
| colspan="3" style="text-indent:2em" | 102.99(6) keV
| 57.28(2) min
| 7/2+
|
|
|-
| <sup>82</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 48
| 81.9166994(22)
| 97(5)E+18 a
| 0+
| 0.0873(22)
|
|-
| <sup>83</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 49
| 82.919118(4)
| 22.3(3) min
| 9/2+
|
|
|-
| style="text-indent:1em" | <sup>83m</sup>Se
| colspan="3" style="text-indent:2em" | 228.50(20) keV
| 70.1(4) s
| 1/2-
|
|
|-
| <sup>84</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 50
| 83.918462(16)
| 3.1(1) min
| 0+
|
|
|-
| <sup>85</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 51
| 84.92225(3)
| 31.7(9) s
| (5/2+)#
|
|
|-
| <sup>86</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 52
| 85.924272(17)
| 15.3(9) s
| 0+
|
|
|-
| <sup>87</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 53
| 86.92852(4)
| 5.50(12) s
| (5/2+)#
|
|
|-
| <sup>88</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 54
| 87.93142(5)
| 1.53(6) s
| 0+
|
|
|-
| <sup>89</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 55
| 88.93645(32)#
| 0.41(4) s
| (5/2+)#
|
|
|-
| <sup>90</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 56
| 89.93996(43)#
| 300# ms [>300 ns]
| 0+
|
|
|-
| <sup>91</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 57
| 90.94596(54)#
| 270(50) ms
| 1/2+#
|
|
|-
| <sup>92</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 58
| 91.94992(64)#
| 100# ms [>300 ns]
| 0+
|
|
|-
| <sup>93</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 59
| 92.95629(86)#
| 50# ms [>300 ns]
| 1/2+#
|
|
|-
| <sup>94</sup>Se
| style="text-align:right" | 34
| style="text-align:right" | 60
| 93.96049(86)#
| 20# ms [>300 ns]
| 0+
|
|
|}
'''Notes'''
* The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
* Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
* Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.
==See also==
[[Selenium]]
[[Selenium-79]]
== References ==
* Isotope masses from [http://www.nndc.bnl.gov/amdc/index.html Ame2003 Atomic Mass Evaluation] by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in ''Nuclear Physics'' A729 (2003).
* Isotopic compositions and standard atomic masses from [http://www.iupac.org/publications/pac/2003/7506/7506x0683.html Atomic weights of the elements. Review 2000 (IUPAC Technical Report)]. ''Pure Appl. Chem.'' Vol. 75, No. 6, pp. 683-800, (2003) and [http://www.iupac.org/news/archives/2005/atomic-weights_revised05.html Atomic Weights Revised (2005)].
* Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
** Audi, Bersillon, Blachot, Wapstra. [http://amdc.in2p3.fr/web/nubase_en.html The Nubase2003 evaluation of nuclear and decay properties], Nuc. Phys. A 729, pp. 3-128 (2003).
** National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the [http://www.nndc.bnl.gov/nudat2/ NuDat 2.1 database] (retrieved Sept. 2005).
** David R. Lide (ed.), Norman E. Holden in ''CRC Handbook of Chemistry and Physics, 85th Edition'', online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.
{{Isotope nav | element=selenium | lighter=Isotopes of arsenic | heavier=Isotopes of bromine }}
[[Category:Isotopes|Selenium]]
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